CROSSWORD CHALLENGE for Sinclair ZX-80
by Colin Hogben
from Your Computer, June/July 1981

CROSSWORD allows you to produce a crossword grid and then fill in the
answers without having to touch the newspaper and cover your fingers in
ink. Unfortunately, the electricity used tends to outweigh the saving in
biros, and you cannot use it on the train to work. On the other hand, you
can have a bash at a prize crossword without worrying about making a
mistake - you can write the correct answer over the wrong one.

The first input requested is the size of the grid; common sizes are 13 and
15, but there is space on the 1K ZX-80 for up to 17. Each line of the grid
is entered as a string of zeros and ones, for empty and blacked-out boxes
respectively.

The cursor is controlled by keys 5, 6, 7 and 8. For example, typing 886666
Newline moves the cursor two spaces to the right and down three. To enter a
word in the grid, type EA or ED for across and down clues respectively; a
pointer will appear, then type the word.

[A bug appeared in the printed listing in line 270, which should be POKE
N+P,B and not POKE N+B,B]
